Fragmentation between mental health (MH) and criminal justice (CJ) systems leads to many persons with serious mental illnesses (SMI) being arrested/incarcerated when MH treatment would be more appropriate. The ?criminalization? of such individuals is an extensively documented problem across the U.S. As shown by the Sequential Intercept Model, the main point of intervention within the CJ system to prevent unnecessary arrest/incarceration is the initial encounter between an officer and a person with SMI. This R01 study aims to test the effectiveness of a new police?MH linkage system that, through a prior NIMH R34 project, was shown to be feasible to implement and study, and to have high acceptability among end-users. Our linkage system consists of 3 steps. First, individuals with SMI and a history of CJ involvement give special consent to be included in a database in the state?s CJ information system, and consent for an officer to have a telephone conversation with a Linkage Specialist at the local public MH system where they are or were in treatment. Second, when an officer runs an enrolled participant?s name or identifiers as part of an inquiry (similar to a background check) during an encounter, the officer receives an electronic message that the person is in MH treatment, and to call a number for more information. Third, the Linkage Specialist, who is a licensed MH professional, receives the call and assists the officer by thinking through observed behaviors and potential resolutions. R34 findings indicated that in some cases when an arrest is not obligatory, the officer chose to refer to or transport to MH services instead of making an arrest (and in a number of cases the subject was reconnected to care) because of the information provided. Partnering with our CJ partner, Georgia Bureau of Investigation (which houses Georgia?s CJ databases/information system), as well as 4 public MH agencies covering 25 counties in Georgia, we will conduct a randomized trial of the linkage system involving 1,600 outpatients with SMI. We will test the hypotheses that patients randomized to the linkage system (as compared to those randomized to a database that does not generate the MH notice and phone number) will: (1) be less likely to be arrested, (2) have fewer arrests (both based on administrative (rap sheet) data provided by GBI), and (3) be less likely to have gaps in outpatient MH services, as evidenced by fewer absences from care of >3 months (based on data from the MH agencies? EMRs). We will examine effects of 4 potential moderators: urban v. rural patient site, male v. female sex of the patient, psychotic v. mood disorder, and lower v. higher likelihood of arrest (based on lifetime history of arrests adjusted for age). Once a patient is enrolled into the linkage system, its mechanics are straightforward, and 2 key targets are verifiable. That is, we will show that Target 1 (an electronic ?hit? to the database) and Target 2 (the Linkage Specialist receiving a call) were engaged. The linkage system will not produce effects (reducing arrests and outpatient MH services gaps) if these 2 verifiable events do not occur. If proven effective, we will prepare a toolkit for other jurisdictions.